TESS builds
on NASA's
Kepler [1]} and repurposed K2 missions [2]}. Kepler and K2 discovered nearly 3,000 confirmed exoplanets with thousands more awaiting confirmation or validationNASA Exoplanet Archive, accessed 14 August 2020.
While the original Kepler mission stared deeply into a single field of 116 square degrees to produce a statistical sample of exoplanetsKepler targets were typically 700-1100 pc distant [3]} in the observation “cone,” TESS is conducting a survey of nearby, bright stars. These targets are the most accessible to both ground and space-based follow-up, necessary for measuring planet mass and density [4]}, [5]}, as well as characterizing atmospheres. Select TESS-discovered planets will likely be good targets for observing with the upcoming James Webb Space Telescope (JWST) for atmospheric characterization.
Some TESS targets are already being characterized by the Hubble Space Telescope (HST), with 12 HST programs awarded observing time for this purpose to date, e.g. TOI-1231 b [6]}, AU Mic b [7]}, [8]}, and many others.
